TWI540160B - A resin composition - Google Patents

Description

Resin composition

The present invention relates to a resin composition which is excellent in mechanical strength and has a good appearance of a product. More specifically, the present invention relates to a resin composition containing two kinds of magnesium compounds and having excellent mechanical strength and a good appearance of the molded article.

In recent years, energy prices have become more and more inclined. Therefore, energy conservation has become a common issue in a wide range of fields. For example, in the automotive field, as a means of improving fuel efficiency, the weight of the vehicle body is reduced. This system uses a metal with a large specific gravity instead of a plastic with a small specific gravity to achieve weight reduction. However, in order to achieve this, it is necessary to overcome the elastic modulus (rigidity), heat distortion temperature, heat shrinkage rate, and the like which are weak points of the resin by using an excellent reinforcing agent.

In response to this requirement, acicular alkaline magnesium sulfate has become a desirable material. The acicular alkaline magnesium sulfate has a fine needle-like crystal shape and a chemical composition of MgSO ₄ . 5Mg(OH) ₂ . 3H ₂ O, a reinforcing agent having a thickness (w) of 0.2 to 1 μm and a length (L) of 10 to 150 μm. Although the acicular alkaline magnesium sulfate is excellent in reinforcement such as bending elastic modulus (rigidity), there is a problem in impact strength and smoothness of the surface of the molded article.

An object of the present invention is to provide a resin composition which overcomes the disadvantages of acicular alkaline magnesium sulfate and which can obtain a good balance between mechanical strength, moldability, and appearance of a molded article.

The present inventors have found that if a resin (component A) is used together with a plate-like magnesium hydroxide (B component) and acicular alkaline magnesium sulfate (component C), the mechanical strength is synergistically enhanced, and the appearance of the molded article is improved, and the present invention has been completed.

That is, the resin composition of the present invention contains (i) 100 parts by weight of a resin (component A); (ii) a plate-shaped hydroxide having a crystal thickness (y) of 0.2 μm or less and a width-to-depth ratio of 20 to 100. Magnesium (B component); and (iii) acicular alkaline magnesium sulfate (component C); the total content of the component B and the component C is 1 to 100 parts by weight based on 100 parts by weight of the resin, and the component B and C The weight ratio of the components is B component: C component = 0.1 to 0.9: 0.9 to 0.1.

Fig. 1 is a SEM photograph of the plate-like magnesium hydroxide obtained in Synthesis Example 1.

Fig. 2 is a schematic view showing the shape of magnesium hydroxide in the form of a plate.

Fig. 3 is a schematic view showing the shape of acicular alkaline magnesium sulfate.

<Plate magnesium hydroxide (B component)>

The crystal grain thickness (y) of the plate-like magnesium hydroxide (component B) is 0.2 μm or less, preferably 0.01 to 0.2 μm, more preferably 0.1 μm or less, and still more preferably 0.06 μm or less. The width (x) of the crystal is preferably 0.5 μm to 10 μm, more preferably 2 to 10 μm, and still more preferably 3 to 10 μm. Further, the crystal thickness (y) and the width (x) were measured by AFM and determined by the average value of 10 crystals.

The aspect ratio (H _B ) is expressed by the ratio of the width (x) to the crystal thickness (y). The higher the aspect ratio of the plate-like magnesium hydroxide (component B), the higher the bending elastic modulus and the like tend to be. Therefore, the plate-like magnesium hydroxide (component B) has a width to depth ratio of 20 to 100. The lower limit of the aspect ratio is preferably 30 or more, more preferably 40 or more. The plate-like magnesium hydroxide (component B) is close to a hexagonal plate crystal. The schematic shape of the plate-like magnesium hydroxide (component B) is shown in 2.

The plate-like magnesium hydroxide (component B) is represented by the following composition formula: Mg(OH) ₂

The plate-like magnesium hydroxide (component B) preferably has a crystal thickness (y) of 0.2 μm or less and a width to depth ratio of 30 or more. Further, the plate-like magnesium hydroxide (component B) preferably has a crystal thickness (y) of 0.1 μm or less and a width to depth ratio of 40 or more.

The plate-like magnesium hydroxide (component B) can be produced by the method described in International Publication No. 2012/050222. In other words, a salt of a monobasic acid and magnesium is added to a monobasic organic acid or an alkali metal salt thereof in the presence of a monobasic organic acid or an alkali metal salt thereof to form a base having an equivalent or less to be coprecipitated, and then subjected to hydrothermal treatment at 100 to 250 ° C.

Examples of the salt of the monobasic acid and magnesium include magnesium chloride and magnesium nitrate.

Examples of the base system include alkali metal hydroxide, calcium hydroxide, and ammonia. The amount of the base is preferably from 1 to 1.0, more preferably from 0.6 to 0.8 equivalents per 1 equivalent of the magnesium chloride.

Examples of the monobasic organic acid include acetic acid, propionic acid, butyric acid and the like. The amount of the monobasic organic acid is preferably from 10 to 200 mol%, more preferably from 50 to 100 mol%, relative to the magnesium chloride.

Examples of the alkali metal system of the monobasic organic acid include sodium acetate, sodium propionate, and sodium butyrate. The alkali metal amount of the monobasic organic acid is preferably 10 to 200 mol%, more preferably 30 to 100 mol%, relative to the magnesium chloride.

The temperature of the hydrothermal treatment is 100 to 250 ° C, preferably 120 to 200 ° C, and 20 to 48 hours, preferably 2 to 12 hours.

Here, the addition of the monobasic organic acid or its alkali metal salt may also be carried out after the co-precipitation reaction and before the hydrothermal treatment. After the hydrothermal treatment, the conventional steps such as filtration, water washing, surface treatment, dehydration, granulation, drying, pulverization, and classification may be appropriately selected.

<Acicular alkaline magnesium sulfate (component C)>

The chemical composition of the acicular alkaline magnesium sulfate (component C) is expressed by the following formula: MgSO ₄ . 5Mg(OH) ₂ . 3H ₂ O

The acicular alkaline magnesium sulfate (component C) is needle crystal.

The thickness (w) is preferably 0.2 to 1 μm, more preferably 0.5 to 1 _μm .

The length (L) is preferably 10 to 100 μm, more preferably 20 to 50 μm, and still more preferably 10 to 50 μm.

The aspect ratio (Hc) [length (L) / thickness (w)] is preferably 20 or more, more preferably 30 to 100. Further, it is preferred to be close to a monodispersion in which each crystal is not aggregated.

The schematic shape of the acicular alkaline magnesium sulfate (component C) is shown in Fig. 3 .

The acicular alkaline magnesium sulfate (component C) preferably has a thickness (w) of 0.5 to 1 μm, a length (L) of 20 to 50 μm, and a width to depth ratio of 20 or more.

The acicular alkaline magnesium sulfate (component C) is added with a small amount of magnesium hydroxide, magnesium oxide, alkali hydroxide or the like in an aqueous solution of magnesium sulfate in an aqueous solution of magnesium sulfate, and then 120 to 250. °C can be manufactured by hydrothermal treatment for 1 to 10 hours. The amount of the base is preferably 1 to 5 moles, more preferably 1 to 3 moles, per mole of magnesium sulfate.

The temperature of the hydrothermal treatment is preferably 120 to 250 ° C, more preferably 150 to 190 ° C. The time of the hydrothermal treatment is preferably 1 to 10 hours, more preferably 4 to 8 hours.

The total content of the component B and the component C is from 1 to 100 parts by weight, preferably from 1 to 70 parts by weight, more preferably from 1 to 50 parts by weight, per 100 parts by weight of the resin.

The weight ratio of the plate-like magnesium hydroxide (component B) to the acicular alkaline magnesium sulfate (component C) used in the present invention is a component B: C component = 0.1 to 0.9: 0.9 to 0.1, preferably 0.2 to 0.6: 0.8~0.4.

The plate-like magnesium hydroxide (component B) and the acicular alkaline magnesium sulfate (component C) used in the present invention may be used as they are, but may also be used, for example, an anionic surfactant, a decane coupling agent, or titanium. The acid ester coupling agent, the aluminum coupling agent, the phosphate ester, the metal fatty acid, and the like are used after being subjected to surface treatment. The amount of the surface treatment agent is 0.1 to 10% by weight, preferably 0.5 to 5% by weight based on the component B and the component C, respectively. The surface treatment method can be carried out in a conventional wet or dry manner.

Further, the above-mentioned reinforcing agent may be used after granulation according to a conventional method. Thereby, the volume of the resin can be approached, and it is connected with the kneading workability and the improvement of the kneading property with the resin.

<Resin (Component A)>

The resin (component A) used in the present invention is at least one selected from the group consisting of thermoplastic resins, thermosetting resins, and rubbers. For example, polyethylene, a copolymer of ethylene and an α-olefin, a copolymer of ethylene and vinyl acetate, a copolymer of ethylene and ethyl acrylate, a copolymer of ethylene and methyl acrylate, polypropylene or propylene and other α may be mentioned. - a copolymer of olefin, polybutene-1, poly-4-methylpentene-1, polystyrene, a copolymer of styrene and acrylonitrile, a copolymer of ethylene and propylene-diene rubber or butadiene , polyvinyl acetate, polyvinyl alcohol, polyacrylate, polymethacrylate, polyurethane, polyester, polyether, polyamine, ABS, polycarbonate, polyphenylene sulfide and other thermoplastic resins .

Further, examples thereof include thermosetting resins such as phenol resin, melamine resin, epoxy resin, unsaturated polyester resin, and alkyd resin.

Further, examples thereof include EPDM, SBR, NBR, ethylene and other α-olefins, such as copolymerized rubber such as propylene or octene. Further, exemplified: butyl rubber, chloroprene rubber, isoprene rubber, chlorosulfonated rubber, ruthenium rubber, fluororubber, chlorobutyl rubber, bromobutyl rubber, epichlorohydrin rubber, chlorine Polyethylene rubber, etc.

<Other ingredients>

The resin composition of the present invention may contain a reinforcing agent such as talc or mica in addition to the components A to C. The content of the reinforcing agent is 1 to 50 parts by weight based on 100 parts by weight of the resin (component A).

Further, in addition to the reinforcing agent, other additives such as an antioxidant, a UV absorber, a slip agent, a crystal nucleating agent, a pigment, a flame retardant, and a filler may be appropriately selected and used. The content of the antioxidant, the ultraviolet absorber, the crystal nucleating agent, and the pigment is preferably 0.01 to 5 parts by weight per 100 parts by weight of the resin (component A). The amount of the slip agent is preferably 0.1 to 5 parts by weight based on 100 parts by weight of the resin (component A). The content of the flame retardant and the filler is preferably from 1 to 50 parts by weight per 100 parts by weight of the resin (component A).

Example

Hereinafter, the present invention will be described in more detail by way of examples, but the invention is not limited to the examples.

Synthesis Example 1 <Manufacture of plate-like magnesium hydroxide (component B)>

In a mixed solution of primary reagent magnesium chloride and sodium acetate (Mg = 2 mol / L, sodium acetate = 2 mol / L, 30 ° C) 20 L, with stirring, add 4 mol / L of primary reagent sodium hydroxide The reaction was carried out by taking 16 L of an aqueous solution (30 ° C). The reactant was charged into a 50 L hot pressing pot In the middle, a hydrothermal treatment was carried out at 160 ° C for 5 hours. The hydrothermally treated product was taken out, filtered under reduced pressure, and washed with water, and then the filter cake was dispersed in water using a stirrer. After heating to 80 ° C, 40 g of stearic acid (purity: 90%) was neutralized with sodium hydroxide, and 1 L of the heated and dissolved aqueous solution was added under stirring to carry out a surface treatment. Thereafter, filtration under reduced pressure, washing with water, extrusion granulation, and drying were carried out. A part of the sample before the surface treatment was subjected to X-ray diffraction, and the BET was measured by AFM and liquid nitrogen adsorption.

The result of X-ray diffraction was identified as magnesium hydroxide. As a result of AFM measurement, each crystal system was close to a hexagonal plate-like outer shape, and the thickness (y) was 0.07 μm and the width (x) was 3.5 μm. Therefore, the aspect ratio is 50. The BET specific surface area is 12 m ² /g. Set it to B-1.

Synthesis Example 2 <Manufacture of plate-like magnesium hydroxide (component B)>

In 400 mL of a mixed aqueous solution of magnesium chloride and sodium acetate (Mg = 4 mol/L, sodium acetate = 2 mol/L, 30 ° C), 4 mol/L sodium hydroxide solution (30 ° C) was added with stirring. 120 mL was allowed to react. The reactant was placed in a 1 L hot press and subjected to a hydrothermal treatment at 170 ° C for 4 hours. The hydrothermally treated product was taken out, filtered under reduced pressure, and washed with water, and then the filter cake was dispersed in water using a stirrer. After heating to 80 ° C, 1 g of stearic acid (purity: 90%) was neutralized with sodium hydroxide, and 50 mL of a heated and dissolved aqueous solution was added thereto with stirring to carry out a surface treatment. Thereafter, filtration under reduced pressure, washing with water, extrusion granulation, and drying were carried out. A part of the sample before the surface treatment was subjected to X-ray diffraction, and the BET was measured by AFM and liquid nitrogen adsorption.

The result of X-ray diffraction was identified as magnesium hydroxide. As a result of AFM measurement, each crystal system was close to a hexagonal plate-like outer shape, and the thickness (y) was 0.055 μm and the width (L) was 3.85 μm. Therefore, the aspect ratio is 70. The BET specific surface area was 7.8 m ² /g. Set it to B-2.

Synthesis Example 3 <Manufacture of acicular alkaline magnesium sulfate (component C)>

To 30 L of a primary reagent magnesium sulfate aqueous solution (1 mol/L, 30 ° C), magnesium hydroxide (Kisma 5 manufactured by Kyowa Chemical Industry Co., Ltd.) 2 mol was added, and after mixing by a stirrer, a 50 L hot press was charged. In the middle, a hydrothermal treatment was carried out for 10 hours at 180 °C. The treated material was filtered under reduced pressure and washed with water to be dispersed in water. After heating to 80 ° C, 4 g of stearic acid (purity: 90%) was neutralized with sodium hydroxide, and the solution dissolved by heating was added under stirring to carry out a surface treatment. Thereafter, filtration under reduced pressure, extrusion granulation, and drying were carried out. A part of the sample before the surface treatment was taken, and X-ray diffraction and AFM measurement were performed.

As a result of X-ray diffraction, it was identified as a crystal having a composition represented by the following formula. As a result of measurement by AFM, the crystal shape was needle-like, and the diameter was 0.8 μm and the long diameter system was 40 μm. Therefore, the aspect ratio is 50.

MgSO ₄ . 5Mg(OH) ₂ . 3H ₂ O

[Example 1]

The plate-like magnesium hydroxide B-1 (component B) obtained in Synthesis Example 1 and the acicular alkaline magnesium sulfate (component C) obtained in Synthesis Example 3 were mixed in accordance with the following formulation, and then biaxially extruded. The machine was discharged into a pellet by melt-kneading at 230 °C. Using the obtained pellets, a test piece was prepared at 230 ° C by an injection molding machine, and physical properties were measured. The results are shown in Table 1.

With respect to polypropylene (melt flow index = 1010 g/10 min): 64.9 wt% and EO rubber (ethylene-octene copolymer rubber): 20 wt% total 100 parts by weight, plate-like magnesium hydroxide (component B): 3.5 parts by weight

Acicular alkaline magnesium sulfate (component C): 14.1 parts by weight

Total of component B and component C: 17.7 parts by weight

Antioxidant: 0.12 parts by weight

[Embodiment 2]

A resin composition was produced and evaluated in the same manner as in Example 1 except that the weight ratio of the component B to the component C was changed to a component B: C component = 0.4: 0.6. The results are shown in Table 1.

[Example 3]

A resin composition was produced and evaluated in the same manner as in Example 1 except that the weight ratio of the B component to the C component was changed to a B component: C component = 0.6: 0.4. The results are shown in Table 1.

[Comparative Examples 1, 2 and 3]

The plate-like magnesium hydroxide B-1 (component B) obtained in Synthesis Example 1, needle-shaped basic magnesium sulfate (component C), and talc (average secondary particle diameter = 6.9 μm, BET = 8 m ² /g), respectively The physical properties when used alone (Comparative Examples 1, 2 and 3, respectively) are shown in Table 1.

Here, MFR means a melt flow index which is an index of moldability (forming speed), and the higher the value, the higher the forming speed.

From the results of Table 1, it was found that the combination of the plate-like magnesium hydroxide (component B) and the acicular alkaline magnesium sulfate (component C) can eliminate the Izod impact strength which is a disadvantage of the latter and the surface roughness of the molded article (appearance) Poor), and having a bending elastic modulus characteristic of acicular alkaline magnesium sulfate (component C) can be a good blending region using acicular alkaline magnesium sulfate (component C) alone or in combination, and it is known that it is used in combination. It has a multiplier effect.

[Example 4]

The plate-like magnesium hydroxide B-2 (component B) obtained in Synthesis Example 2 and the acicular alkaline magnesium sulfate (component C) obtained in Synthesis Example 3 were kneaded together with talc widely used as a resin reinforcing agent. . The test piece was produced in the same manner as in Examples 1, 2 and 3. The results are shown in Table 2.

Relative to polypropylene (melt flow index = 1010 g/10 min): 64.9 wt% and EO rubber (ethylene-octene copolymer rubber): 20 wt% total 100 parts by weight, talc: 11.8 parts by weight

Plate-shaped magnesium hydroxide B-2 (component B): 1.2 parts by weight

Acicular alkaline magnesium sulfate (component C): 4.7 parts by weight

Total of component B and component C: 5.9 parts by weight

Antioxidant: 0.12 parts by weight

[Example 5]

A resin composition was produced and evaluated in the same manner as in Example 4 except that the weight ratio of the component B to the component C was changed to a component B: C component = 0.4: 0.6. The results are shown in Table 2.

[Comparative Examples 4 and 5]

The physical properties of the plate-like magnesium hydroxide B-2 (component B) and the acicular alkaline magnesium sulfate (component C) obtained in Synthesis Example 2 when used alone in combination with talc (Comparative Examples 4 and 5, respectively) are shown in Table 2.

As a result of the results of Table 2, even if a talc-filled resin molded product was used, the synergistic effect was confirmed by mechanical strength by using plate-like magnesium hydroxide (component B) and acicular magnesium sulfate (component C) in combination.

(cf. the efficacy of prior art)

The resin composition of the present invention is excellent in mechanical strength such as bending elastic modulus and impact strength. Further, the resin composition of the present invention is excellent in moldability and appearance of a molded article. According to the present invention, by using the plate-like magnesium hydroxide (component B) in combination, it is possible to eliminate the impact strength which is a disadvantage of the acicular alkaline magnesium sulfate (component C) and the surface unevenness (roughness) of the molded article. Further, according to the present invention, the plate-like magnesium hydroxide (component B) is used in combination, and the excellent bending elastic modulus characteristic of the acicular alkaline magnesium sulfate (component C) is compared with the case where the component C is used alone. Multiplicative improvement. Therefore, there are also new options for reducing the amount of fortifier blending. In other words, a lightweight resin composition can be provided by the separate use of acicular alkaline magnesium sulfate (component C).

Claims (6)

A resin composition comprising: (i) 100 parts by weight of a resin (component A); (ii) a plate-like magnesium hydroxide having a crystal thickness (y) of 0.2 μm or less and a width-to-depth ratio of 20 to 100 (component B) (iii) acicular alkaline magnesium sulfate (component C); and (iv) at least one enhancer (component D) selected from the group consisting of talc and mica; total content of component B and component C It is 1 to 100 parts by weight based on 100 parts by weight of the resin (component A), and the weight ratio of the component B to the component C is B component: C component = 0.1 to 0.9: 0.9 to 0.1, and the content of the component D is relative to 100 parts by weight of the resin (component A) is 1 to 50 parts by weight. The resin composition of the first aspect of the patent application, wherein the weight ratio of the B component to the C component is B component: C component = 0.2 to 0.6: 0.8 to 0.4. The resin composition of the first aspect of the invention is characterized in that the crystal thickness (y) of the component B is 0.2 μm or less and the aspect ratio is 30 or more. The resin composition of the first aspect of the invention is characterized in that the crystal thickness (y) of the component B is 0.1 μm or less and the aspect ratio is 40 or more. The resin composition of the first aspect of the invention is characterized in that the thickness (w) of the component C is 0.5 to 1 μm, the length (L) is 20 to 50 μm, and the aspect ratio is 20 or more. The resin composition of claim 1, wherein the component B and the component C are surface-treated with an anionic surfactant.